Neal could be even more important going forward, after starting point guard Tony Parker revealed fresh concerns about his sore hamstring. He plans to get an MRI on Wednesday.

Duncan bounced back from his worst game ever in the finals, and the Spurs’ combination of fresh faces and old reliables dominated the NBA’s winningest team before an eager crowd that hadn’t seen the finals here since 2007.

”It shouldn’t be a surprise,” said Spurs coach Gregg Popovich. ”These are the last two teams standing. I don’t think either one of them is going to get down if they have a bad night.”

The Spurs were as good as fans remembered in the old days, shutting down James until they had built a huge lead late in the third quarter.

James finished with 15 points and 11 rebounds, but missed 11 of his first 13 shots against the excellent defense of Kawhi Leonard, who had 14 points and 12 rebounds.

”Honestly, I just have to play better,” James said. ”I can’t have a performance like tonight and expect to win.”

Game 4 is Thursday here, where the Heat are 3-22 in the regular season and so far zero wins and one really bad beating in the postseason.

”We got what we deserved,” Heat coach Erik Spoelstra said. ”I didn’t even recognize the team that was out there tonight.”

Duncan shot 3 of 13 for nine points, his worst performance ever in his 25 NBA Finals games, in the Heat’s 103-84 victory Sunday. Parker wasn’t much better, shooting 5 of 14 and committing five turnovers, and Manu Ginobili admitted afterward the veteran trio had to play well for the Spurs to win.

They were fine, but the lesser-knowns were better.

Parker and Ginobili combined for 14 assists, but the bigger story was the guys who had never played on this stage before.

– Neal, who went undrafted after playing for LaSalle and Towson, then playing overseas for three seasons in Italy, Spain and Turkey.

-Green, who had been cut multiple times – including by James’ Cavaliers – and now has the shot to stick.

-Leonard, the draft-night trade acquisition from San Diego State who played the NBA’s four-time MVP to a stalemate.

”It’s a dream come true,” Neal said. ”Me and Danny both went through a lot of stuff together. We were guys that showed up two hours before practice started to get shots up and to prove to the coaching staff that we belong, and we’re going to do whatever we need to do to get minutes.

”So me and Danny, we were able to play great tonight.”

Mike Miller made all five 3-pointers and scored 15 points for the Heat, who broke open Sunday’s game and seized momentum in the series with a 33-5 run in the second half.

The Spurs seized it right back, improving to 18-7 in the finals, the best winning percentage of any team with 20 or more games.

A brief flurry by James had Miami within 15 after three quarters, but Neal, Green and Leonard combined on a 13-0 run to open the fourth, Green’s 3-pointer making it 91-63.

”All of my teammates and Pop. They do a great job of encouraging me. They continue to tell me to shoot the ball. They continue to tell me whenever I’m open, to let it fly,” Green said.

The NBA hadn’t made its way along San Antonio’s River Walk this late in the season since 2007, and fans couldn’t wait to have the Spurs back. They sang and danced and clapped around the concourse and in their seats, as if their favorite rock band had returned for a concert.

And they were thrilled to see the Duncan they recognized from his first 24 finals appearances.

He got right on the board in this one, with a short jumper 20 seconds into the game. The Spurs, who had played from behind most of the series, had a 24-20 lead after making 11 of 18 shots in the first quarter.

Duncan hit a pair of three throws and another basket, and after a jumper by Neal, he threw a long outlet to Leonard for a dunk that made it 40-30.

Neal’s 3 made it 43-32, but Miller hit a pair of 3-pointers in a 12-1 run that tied it at 44 with 37 seconds in the half, the Heat appearing set to go into the half with momentum. But Parker drilled a 3 from the corner, and after Green blocked James’ shot, the Spurs rushed it up for a 3-pointer by Neal that fell at the buzzer, the reserve guard pointing back toward his defenders before the Spurs headed to the locker room with a 50-44 advantage.

The party played on all right, with a huge roar when Tracy McGrady, a former perennial All-Star now in his first finals appearance as a member of the Spurs’ bench, checked in midway through the fourth quarter. He was scoreless with three assists.

James started 2 for 13, then made his final four shots of the third as the Heat got within 13 before Ginobili fired a nifty pass to Tiago Splitter under the basket for a score with 0.1 seconds remaining, making it 78-63 and setting the stage for the big fourth-quarter finish.

”They came out in the third quarter and they kicked our butt pretty good and frustration started to set in,” the Heat’s Dwyane Wade said.

It was a potentially pivotal victory for the Spurs in their quest to go 5 for 5 in the finals. Since the NBA Finals went to a 2-3-2 format in 1985, the Game 3 winner when the series was tied 1-1 has gone on to win 12 of the 13 titles – though the Heat were the lone one that didn’t, in 2011.

Notes: The previous NBA Finals record for a team was 14 3-pointers, held by three teams. … Miami’s first victory in San Antonio came on Dec. 23, 1996, in its 11th try. David Robinson broke his left foot in the second quarter of the Heat’s 90-79 victory, missed the rest of the season, and the Spurs fell into the lottery, which they ended up winning so they could take Duncan with the No. 1 pick in the 1997 draft.